As mobile devices become more popular and useful, they are used frequently for varied purposes. A typical mobile device has limited battery life and frequent use, especially of battery-intensive applications, cause the battery to be drained quickly and limits the usefulness of the mobile device. Conventional techniques to conserve battery life include dimming or turning off the display of the mobile device when the user is not using the display. To protect the contents of the mobile device, the device is typically password protected. For example, when a device is turned on or woken up, a lock screen is displayed and a user enters a password to access the contents of the mobile device protected by the lock screen.
In one aspect, conventional methods of waking a processor on a device are not power efficient. For example, a display is inadvertently turned on or a device is unintentionally woken up. In another aspect, conventional means of wirelessly exchanging information using mobile devices are sometimes insecure and often cumbersome and inconvenient. For example, to use a functionality (e.g., an application) on the mobile device, the user wakes a processor on a device by unlocking the device and opening the application. The steps of waking and/or unlocking a device can be inefficient and tedious, especially when repeated within a short period of time.